JP2010085170A - Voltage measuring method and voltage measuring device of battery cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten a time required for a series of voltage measurement to a plurality of battery cells. <P>SOLUTION: A voltage measuring method includes a connection process for connecting a capacitor C in parallel with the battery cell CL in a battery cell unit 2, a charging process for charging the capacitor C by the battery cell CL, a measuring process for measuring a voltage of the capacitor C, and a storage process for storing a voltage value measured in the measuring process. The first switch circuit 41 connects the positive electrode side of the battery cell CL to one terminal of the capacitor C, and simultaneously connects the negative electrode side of the battery cell CL to the other terminal of the capacitor C. In the connection process, when measuring a voltage of one battery cell CL and then measuring a voltage of the next battery cell CL, the capacitor C is connected to the next battery cell CL without being discharged. The connection process further includes a rearrangement process for rearranging a measuring order of battery cells CL, etc., in a next measuring series in the order of largeness of each voltage value measured this time, after finish of the measuring series. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a battery cell voltage measuring method and a voltage measuring apparatus for measuring the voltage of each battery cell of a battery cell unit configured by connecting a plurality of battery cells in series.

  In recent years, electric vehicles and hybrid electric vehicles have become widespread, and in such vehicles, a battery cell unit configured by connecting a plurality of battery cells in series is used as a power source for an electric motor.

  In such battery cell units, there are variations in the temperature characteristics and capacities of the battery cells due to variations in manufacturing and variations over time. As described above, when discharging and charging are repeated in a state where the temperature characteristics and capacities of the respective battery cells vary, the voltage of each battery cell varies, and further, depending on the battery cell, overdischarge and overcharge may occur. In order to prevent such overdischarge and overcharge, it is necessary to measure the voltage of each battery cell.

For example, Patent Document 1 discloses a so-called flying capacitor type voltage measurement method. Specifically, in the voltage measurement method according to Patent Document 1, after a capacitor is connected in parallel to a certain battery cell to be measured and the capacitor is charged, the connection between the battery cell and the capacitor is released. The capacitor is connected to a voltage measuring unit, and the voltage of the capacitor is measured by the voltage measuring unit. Thus, the voltage of one battery cell is measured. Subsequently, after discharging the charge accumulated in the capacitor, the capacitor is connected in parallel to the battery cell to be measured next, and the above-described procedure is repeated. Thus, the voltage of all the battery cells in the battery cell unit is measured by executing the above-described procedure while switching the battery cells to which the capacitors are connected in parallel.
JP 2007-40842 A

  By the way, in the configuration in which the voltage of the battery cell is measured in order by repeating the procedure of measuring the voltage of the capacitor after connecting the capacitor to the battery cell and charging as described above, the voltage of one battery cell is measured. Even after the measurement is completed, the electric charge when charged by the battery cell remains in the capacitor. Therefore, in the voltage measurement method disclosed in Patent Document 1, when the voltage measurement of one battery cell is completed and the process proceeds to the voltage measurement of the next battery cell, the charge accumulated in the capacitor is discharged. . By doing so, the electric charge accumulated in the capacitor in this voltage measurement does not affect the voltage measurement of the next battery cell.

  However, if the voltage of the capacitor is reset each time the voltage is measured, it is necessary to charge the capacitor from zero every time when measuring the voltage of each battery cell, and the charging time of the capacitor becomes long. That is, although it is not necessary to be affected by the electric charge accumulated in the capacitor in the previous voltage measurement, the time required to measure the voltage of each battery cell becomes long. When the time for measuring the voltage of each battery cell becomes longer, the time required for a series of voltage measurements for measuring the voltage in order for a plurality of battery cells also becomes longer.

  In addition, a discharge time is required to discharge the capacitor between the voltage measurement of one battery cell and the voltage measurement of the next battery cell. It takes a long time to measure a series of voltage measurements.

  This invention is made | formed in view of this point, The place made into the objective is to shorten the time which a series of voltage measurement with respect to several battery cell requires.

  The present invention rearranges the measurement order when measuring the voltage of a plurality of battery cells based on the magnitude of the voltage of the capacitor charged by each battery cell.

  Specifically, according to a first aspect of the present invention, in a battery cell unit configured by connecting a plurality of battery cells in series, a connection step of connecting a capacitor to the battery cell in parallel via a connection circuit, and the battery A charging step of charging the capacitor in the cell; a measurement step of measuring the voltage of the capacitor as the voltage of the battery cell after disconnecting the battery cell and the capacitor; and a voltage value measured in the measurement step And a storage step for storing the voltage, and a battery cell voltage measurement method for measuring a voltage for each of the plurality of battery cells in order and performing a series of voltage measurements. The connection circuit is configured to connect the positive electrode side of each battery cell to one terminal of the capacitor, and to connect the negative electrode side of each battery cell to the other terminal of the capacitor. After measuring the voltage of one battery cell, when measuring the voltage of the next battery cell, the capacitor is not discharged after the measurement step for the one battery cell, After connecting to the cell and finishing a series of voltage measurements for the plurality of battery cells, the measurement order of the plurality of battery cells in the next series of voltage measurements is changed in the order of the voltage values measured this time. It further includes a rearrangement step of rearranging.

  In the case of the above configuration, after the voltage measurement of one battery cell is completed, the capacitor is not discharged before the voltage measurement of the next battery cell is performed. The charge at the time of voltage measurement of the previous battery cell remains in the capacitor. That is, when the capacitor is connected in parallel to the next battery cell, the capacitor is not charged from zero, but is charged from a state in which a charge corresponding to the voltage of the previous battery cell remains. At this time, since the positive electrode side of each battery cell is connected to one terminal of the capacitor and the negative electrode side of each battery cell is connected to the other terminal of the capacitor, the sign of the voltage applied to the capacitor does not change.

  Here, in the present invention, every time a series of voltage measurements for a plurality of battery cells is completed, the measurement order of the battery cells in the next series of voltage measurements is rearranged in the rearrangement step. Specifically, the measurement order of the battery cells is rearranged in the order of the magnitude of the voltage value measured this time (that is, in order of increasing voltage value or decreasing voltage value). Here, since the voltage of each battery cell does not change greatly after the series of voltage measurements is completed until the next series of voltage measurements is performed, the next time in the order of the voltage values measured this time. When the voltage of the battery cells is measured, the voltage values of the battery cells measured in turn next time are arranged in the order of magnitude, and the voltage difference between the battery cells measured continuously becomes small.

  Thus, when the voltage difference between the battery cells measured continuously is small, when the capacitor is connected to the battery cell, the capacitor that increases or decreases the voltage of the capacitor to match the voltage of the connected battery cell. The amount of charge can be made small. That is, when a capacitor is connected to a battery cell, the capacitor already stores a charge amount corresponding to the voltage of the previous battery cell, and the voltage of the previous battery cell and the voltage of the current battery cell are stored. Since the difference is small, the amount of charge to be charged by the current battery cell with respect to the capacitor in which the charge remains is small. As a result, the voltage of the capacitor can be quickly converged to the voltage of the connected battery cell.

  In addition, when the voltage of the capacitor in which the charge remains is higher than that of the battery cell to be measured, the capacitor is discharged from the capacitor to the battery cell. Since a small amount is sufficient, the voltage of the capacitor is quickly converged to the voltage of the battery cell to be measured.

  Thus, since the charging time of each battery cell can be shortened, the time required to complete a series of voltage measurements of a plurality of battery cells can be shortened. Further, since it is not necessary to discharge the capacitor between the voltage measurement of one battery cell and the voltage measurement of the next battery cell, also in this respect, until a series of voltage measurement of a plurality of battery cells is completed. Can be shortened.

  According to a second invention, in the first invention, the rearranging step is configured such that the measurement order of the plurality of battery cells is an arrangement in which the magnitude of the voltage value is ascending order, and the magnitude of the voltage value is in descending order. In such an arrangement, it is assumed that the voltage is alternately switched for each series of voltage measurements.

  In the case of the above configuration, when the current series of voltage measurements are performed in a measurement order in which the magnitudes of the voltage values are in ascending order, the next series of voltage measurements are performed in descending order of the voltage values. The measurement order is as follows. Further, the series of voltage measurements one after another is performed in a measurement order in which the magnitude of the voltage value is in ascending order. In this way, each time a series of voltage measurements is performed, the voltage value of the last battery cell in a series of voltage measurements and the next series are changed by switching the order of voltage values in descending order and ascending order. The difference from the voltage of the first battery cell in the voltage measurement can be reduced.

  That is, when a series of voltage measurements are performed in a measurement order in which the magnitude of the voltage value is ascending, the battery cell having the highest voltage among the plurality of battery cells is measured last. Since the next series of voltage measurements are performed in a measurement order in which the magnitude of the voltage value is descending, the battery cell having the highest voltage among the plurality of battery cells is measured first. Conversely, when a series of voltage measurements are performed in a measurement order in which the magnitude of the voltage value is in descending order, the battery having the lowest voltage among the plurality of battery cells in the series of voltage measurements. The cell is measured last, and then in a series of voltage measurements, the battery cell with the lowest voltage among the plurality of battery cells is measured first.

  In the present invention, since the charge at the time of voltage measurement of the previous battery cell remains in the capacitor connected to the battery cell, when measuring the voltage of the first battery cell in a series of voltage measurement, The charge at the time of voltage measurement of the last battery cell in the previous series of voltage measurement remains in the capacitor.

  In other words, in a series of consecutive voltage measurements, by reducing the voltage difference between the last battery cell of a series of voltage measurements performed earlier and the first battery cell of a series of subsequent voltage measurements, When charging the capacitor with the first battery cell of the measurement, since the capacitor has already accumulated a charge close to the amount of charge corresponding to the voltage of the first battery cell, the charge of the capacitor to be increased or decreased The amount may be small, and the voltage of the capacitor can be quickly converged to the voltage of the connected battery cell. By doing so, the charging time of the first battery cell in a series of voltage measurements can be shortened.

  According to a third aspect of the present invention, in a battery cell unit configured by connecting a plurality of battery cells in series, a connection step of connecting a capacitor to the battery cell in parallel via a connection circuit; and the capacitor in the battery cell A charging step of charging, a measurement step of measuring the voltage of the capacitor as the voltage of the battery cell after disconnecting the battery cell and the capacitor, and a storage step of storing the voltage value measured in the measurement step And measuring the voltage of each battery cell in order with respect to a plurality of the battery cells, and performing a series of voltage measurements. The connection circuit connects the positive electrode side of the odd-numbered battery cells in the series connection among the plurality of battery cells to one terminal of the capacitor and the negative electrode side of the odd-numbered battery cells to the capacitor While connecting to the other terminal, the positive electrode side of the even-numbered battery cell in the series connection among the plurality of battery cells is connected to the other terminal of the capacitor and the negative electrode side of the even-numbered battery cell is the It is configured to be connected to one terminal of a capacitor, and in the connecting step, after measuring the voltage of one battery cell, when measuring the voltage of the next battery cell, the capacitor is not discharged. Connecting to the next battery cell, and the measuring step includes connecting the plurality of battery cells in series with an odd group of battery cells having an odd number in the order of connection in series connection. The battery cells included in the other group after grouping into an even group of even-numbered battery cells and measuring the voltage of the battery cell included in one of the groups Shall be measured.

  In the case of the above configuration, after the voltage measurement of one battery cell is completed, the capacitor is not discharged before the voltage measurement of the next battery cell is performed. The charge at the time of voltage measurement of the previous battery cell remains in the capacitor. That is, when the capacitor is connected in parallel to the next battery cell, the capacitor is not charged from zero, but is charged from a state in which a charge corresponding to the voltage of the previous battery cell remains.

  Here, in the present invention, the connection to the capacitor is reversed between the odd-numbered battery cells and the even-numbered battery cells arranged in series. That is, the voltage of the capacitor when charged by the odd-numbered battery cells and the voltage of the capacitor when charged by the even-numbered battery cells are reversed.

  Therefore, in the above-described configuration, the plurality of battery cells are grouped into an odd group composed of odd-numbered battery cells arranged in series and an even group composed of even-numbered battery cells arranged in series. Then, after measuring the voltage of the battery cell included in any one group, the voltage of the battery cell included in the other group is measured. By doing so, the charging time of the battery cell can be shortened.

  That is, when the odd-numbered battery cells and the even-numbered battery cells are alternately charged, the voltage of the capacitor is reversed between positive and negative at every measurement of the battery cells. Here, since the charge at the time of voltage measurement of the previous battery cell remains in the capacitor as described above, if the sign of the voltage of the capacitor is inverted at each voltage measurement, the charge of the capacitor to be increased or decreased The amount becomes very large. As a result, the charging time of the battery cell becomes long.

  On the other hand, in the present invention, the voltage of the capacitor when the capacitor is charged is measured separately for the positive group and the negative group, thereby at least the voltage of the battery cell in the same group. While the measurements are performed in order, it is possible to prevent the polarity of the capacitor voltage from being reversed every time the voltage is measured. As a result, the charging time of the battery cell can be shortened.

  Moreover, since it is not necessary to discharge the capacitor between the voltage measurement of one battery cell and the voltage measurement of the next battery cell, also in this respect, the series of voltage measurement for each group is completed. Time can be shortened.

  According to a fourth invention, in the third invention, after finishing a series of voltage measurements on the plurality of battery cells, the plurality of battery cells in the next series of voltage measurements in each of the odd group and the even group. It is further assumed that an in-group rearrangement step of rearranging the measurement order in the order of the voltage values measured this time is included.

  In the case of the above-mentioned configuration, in each group, by rearranging the measurement order of the battery cells in the next series of voltage measurements in the order of the magnitude of the voltage value measured this time, The voltage difference between the measured battery cells is reduced. If the voltage difference between the battery cells measured continuously is small, as described above, when the capacitor is connected to the battery cell, the capacitor increases or decreases to match the voltage of the connected battery cell. The amount of charge can be made small. As a result, the voltage of the capacitor can be quickly converged to the voltage of the connected battery cell. Thus, since the charging time of each battery cell can be shortened in each of the odd group and the even group, the time required to complete a series of voltage measurements for each group can be shortened.

  According to a fifth invention, in the fourth invention, in the group rearranging step, the measurement order of the plurality of battery cells was measured this time in the group in which voltage measurement was performed first in the next series of voltage measurements. While the voltage values are rearranged in descending order, in the group in which voltage measurement is performed later in the next series of voltage measurements, the measurement order of the plurality of battery cells is determined according to the voltage values measured this time. It shall be rearranged in ascending order.

  In the case of the above configuration, since the sign of the voltage applied to the capacitor is different between the previous group and the subsequent group, when switching from the voltage measurement of the previous group to the voltage measurement of the subsequent group, the sign of the voltage of the capacitor is Inversely, the charge accumulated in the capacitor increases or decreases in large quantities. Then, for the battery cell that is measured first after switching, that is, the battery cell that is measured first in the later group, the time until the voltage of the capacitor converges to the voltage of the battery cell becomes long. It takes a long time to measure the voltage of the cell.

  Therefore, in the fifth invention, in the group in which the voltage is measured first in the next series of voltage measurements, the measurement order of the battery cells is rearranged so that the magnitude of the voltage value is descending, while the next series of voltages is measured. In the group in which the voltage is measured later in the measurement, the measurement order of the battery cells is rearranged so that the magnitude of the voltage value is ascending. In this way, the voltage of the battery cell measured at the end of the previous group is the lowest in the group, and the voltage of the battery cell measured at the beginning of the later group is the lowest in the group. Become. As a result, the difference between the voltage of the capacitor charged by the last battery cell of the previous group and the voltage of the capacitor charged by the first battery cell of the later group can be minimized. It is possible to reduce as much as possible the amount of increase or decrease in the capacitor charge when switching from the voltage measurement of one group to the voltage measurement of the subsequent group. By carrying out like this, the charge time of the 1st battery cell in a subsequent group can be shortened, and the time required for the voltage measurement of this battery cell can be shortened.

  According to a sixth invention, in any one of the third to fifth inventions, the intra-group rearranging step includes a group for measuring voltage and a group for measuring voltage before and after the series of voltage measurement for the plurality of battery cells. The order with the group for voltage measurement shall be changed.

  In the case of the above-described configuration, in a certain series of voltage measurements, when an odd group voltage is measured first and then an even group voltage is measured, the next series of voltage measurements first includes an even group voltage measurement. Voltage measurement is performed, and then an odd group voltage measurement is performed later. Then, a group that is voltage measured later in a series of voltage measurements is the same as a group that is voltage measured earlier in the next series of voltage measurements. As a result, the sign of the capacitor voltage is not reversed when a series of voltage measurements are completed and the next series of voltage measurements is performed. By doing so, the charging time of the first battery cell in a series of voltage measurements can be shortened.

  A seventh invention is a battery cell unit configured by connecting a plurality of battery cells in series, a capacitor connected in parallel to the battery cell via a connection circuit, and a voltage measurement unit for measuring the voltage of the capacitor And connecting the capacitor in parallel to the battery cell via the connection circuit and charging the capacitor with the battery cell, then disconnecting the parallel connection between the capacitor and the battery cell, and the voltage of the capacitor And a storage unit that stores a voltage value measured by the voltage measurement unit, and sequentially measures the voltage of each battery cell with respect to the plurality of battery cells. A battery cell voltage measuring device that performs a series of voltage measurements is an object. The connection circuit is configured to connect the positive electrode side of each battery cell to one terminal of the capacitor, and connect the negative electrode side of each battery cell to the other terminal of the capacitor. After measuring the voltage of one battery cell, when measuring the voltage of the next battery cell, the capacitor is configured to be connected to the next battery cell without discharging. After the series of voltage measurements for the plurality of battery cells is completed, the measurement order of the plurality of battery cells in the next series of voltage measurements is rearranged in the order of the voltage values measured this time.

  In the case of the above configuration, after the voltage measurement of one battery cell is completed, the capacitor is not discharged before the voltage measurement of the next battery cell is performed. The charge at the time of voltage measurement of the previous battery cell remains in the capacitor.

  Here, in the present invention, every time a series of voltage measurements for a plurality of battery cells is completed, the measurement order of the battery cells in the next series of voltage measurements is the order of the magnitude of the voltage value measured this time (that is, The voltage values are sorted in the descending order of the voltage value or the decreasing voltage value. Here, the voltage of each battery cell does not change greatly after the series of voltage measurements is completed until the next series of voltage measurements is performed. Are generally arranged in order of size, and the voltage difference between the battery cells measured continuously becomes small.

  Thus, when the voltage difference between the battery cells measured continuously is small, when the capacitor is connected to the battery cell, the capacitor that increases or decreases the voltage of the capacitor to match the voltage of the connected battery cell. The amount of charge can be made small. As a result, the voltage of the capacitor can be quickly converged to the voltage of the connected battery cell.

  In addition, when the voltage of the capacitor in which the charge remains is higher than that of the battery cell to be measured, the capacitor is discharged from the capacitor to the battery cell. Since a small amount is sufficient, the voltage of the capacitor is quickly converged to the voltage of the battery cell to be measured.

  Thus, since the charging time of each battery cell can be shortened, the time required to complete a series of voltage measurements of a plurality of battery cells can be shortened. Further, since it is not necessary to discharge the capacitor between the voltage measurement of one battery cell and the voltage measurement of the next battery cell, also in this respect, until a series of voltage measurement of a plurality of battery cells is completed. Can be shortened.

  In an eighth aspect based on the seventh aspect, the control unit sets the measurement order of the plurality of battery cells so that the magnitude of the voltage value is in ascending order, and the magnitude of the voltage value is in descending order. In such an arrangement, the voltage is alternately switched for each series of voltage measurements.

  In the case of the above-described configuration, each time a series of voltage measurements is performed, the voltage value of the last battery cell in a series of voltage measurements is changed by switching the order of voltage values in descending order and ascending order. The difference from the voltage of the first battery cell in the series of voltage measurements can be reduced.

  In the present invention, since the charge at the time of voltage measurement of the previous battery cell remains in the capacitor connected to the battery cell, when measuring the voltage of the first battery cell in a series of voltage measurement, The charge at the time of voltage measurement of the last battery cell in the previous series of voltage measurement remains in the capacitor.

  In other words, in a series of consecutive voltage measurements, by reducing the voltage difference between the last battery cell of a series of voltage measurements performed earlier and the first battery cell of a series of subsequent voltage measurements, When charging the capacitor with the first battery cell of the measurement, since the capacitor has already accumulated a charge close to the amount of charge corresponding to the voltage of the first battery cell, the charge of the capacitor to be increased or decreased The amount can be small, and the voltage of the capacitor can be quickly converged to the voltage of the connected battery cell. By doing so, the charging time of the first battery cell in a series of voltage measurements can be shortened.

  A ninth invention is a battery cell unit configured by connecting a plurality of battery cells in series, a capacitor connected in parallel to the battery cell via a connection circuit, and a voltage measurement unit for measuring the voltage of the capacitor And connecting the capacitor in parallel to the battery cell via the connection circuit and charging the capacitor with the battery cell, then disconnecting the parallel connection between the capacitor and the battery cell, and the voltage of the capacitor And a storage unit that stores a voltage value measured by the voltage measurement unit, and sequentially measures the voltage of each battery cell with respect to the plurality of battery cells. A battery cell voltage measuring device that performs a series of voltage measurements is an object. The connection circuit connects the positive electrode side of the odd-numbered battery cells in the series connection among the plurality of battery cells to one terminal of the capacitor and the negative electrode side of the odd-numbered battery cells to the capacitor While connecting to the other terminal, the positive electrode side of the even-numbered battery cell in the series connection among the plurality of battery cells is connected to the other terminal of the capacitor and the negative electrode side of the even-numbered battery cell is the The controller is configured to be connected to one terminal of a capacitor, and the control unit measures the voltage of one battery cell and then measures the voltage of the next battery cell without discharging the capacitor. And an odd group consisting of odd numbered battery cells arranged in series with a plurality of the battery cells connected to the next battery cell. After grouping into even-numbered groups consisting of even-numbered battery cells in the order of connection in the column connection, after measuring the voltage of the battery cells included in any one group, the above-mentioned included in the other group The voltage of the battery cell shall be measured.

  In the case of the above configuration, after the voltage measurement of one battery cell is completed, the capacitor is not discharged before the voltage measurement of the next battery cell is performed. The charge at the time of voltage measurement of the previous battery cell remains in the capacitor.

  Here, in the present invention, the voltage of the capacitor when charged by the odd-numbered battery cells and the voltage of the capacitor when charged by the even-numbered battery cells are reversed.

  Therefore, in the above-described configuration, the plurality of battery cells are grouped into an odd group composed of odd-numbered battery cells arranged in series and an even group composed of even-numbered battery cells arranged in series. Then, after measuring the voltage of the battery cell included in any one group, the voltage of the battery cell included in the other group is measured. By carrying out like this, the charging time of each battery cell can be shortened.

  In other words, by measuring the voltage of the battery cell separately for the positive group and the negative group when the capacitor is charged, at least the voltage measurement of the battery cell is sequentially performed in the same group. During this time, it is possible to prevent the polarity of the capacitor voltage from being reversed every time the voltage is measured. As a result, the charging time of the battery cell can be shortened.

  Moreover, since it is not necessary to discharge the capacitor between the voltage measurement of one battery cell and the voltage measurement of the next battery cell, also in this respect, the series of voltage measurement for each group is completed. Time can be shortened.

  According to a tenth aspect of the present invention, in the ninth aspect of the present invention, after the control unit finishes a series of voltage measurements for the plurality of battery cells, each of the odd number group and the even number group performs a next series of voltage measurements. The measurement order of the plurality of battery cells is rearranged in order of the magnitude of the voltage value measured this time.

  In the case of the above-mentioned configuration, in each group, by rearranging the measurement order of the battery cells in the next series of voltage measurements in the order of the magnitude of the voltage value measured this time, Since the voltage difference between the measured battery cells can be reduced, when the capacitor is connected to the battery cell, the amount of charge on the capacitor that is increased or decreased to match the voltage of the connected battery cell. Can be made small. As a result, the voltage of the capacitor can be quickly converged to the voltage of the connected battery cell. Thus, since the charging time of each battery cell can be shortened in each of the odd group and the even group, the time required to complete a series of voltage measurements for each group can be shortened.

  In an eleventh aspect, in the tenth aspect, in the group in which the controller first measures the voltage in the next series of voltage measurements, the measurement order of the plurality of battery cells is set to the voltage value measured this time. In the group in which the voltage is rearranged in descending order, in the group in which voltage measurement is performed later in the next series of voltage measurements, the measurement order of the plurality of battery cells is the ascending order of the voltage values measured this time. It shall be rearranged as follows.

  In the case of the above configuration, since the sign of the voltage applied to the capacitor is different between the previous group and the subsequent group, when switching from the voltage measurement of the previous group to the voltage measurement of the subsequent group, the sign of the voltage of the capacitor is Inversely, the charge accumulated in the capacitor increases or decreases in large quantities. Then, for the battery cell that is measured first after switching, that is, the battery cell that is measured first in the later group, the time until the voltage of the capacitor converges to the voltage of the battery cell becomes long. It takes a long time to measure the voltage of the cell.

  Therefore, in the eleventh aspect of the invention, in the group in which the voltage is measured first in the next series of voltage measurements, the measurement order of the battery cells is rearranged so that the magnitude of the voltage value is in descending order. In the group in which the voltage is measured later in the measurement, the measurement order of the battery cells is rearranged so that the magnitude of the voltage value is ascending. In this way, the voltage of the battery cell measured at the end of the previous group is the lowest in the group, and the voltage of the battery cell measured at the beginning of the later group is the lowest in the group. Become. As a result, the difference between the voltage of the capacitor charged by the last battery cell of the previous group and the voltage of the capacitor charged by the first battery cell of the later group can be minimized. It is possible to reduce as much as possible the amount of increase or decrease in the capacitor charge when switching from the voltage measurement of one group to the voltage measurement of the subsequent group. By carrying out like this, the charge time of the 1st battery cell in a subsequent group can be shortened, and the time required for the voltage measurement of this battery cell can be shortened.

  According to a twelfth aspect, in the eleventh aspect, the control unit switches the order of the group for voltage measurement first and the group for voltage measurement later each time a series of voltage measurement for the plurality of battery cells is completed. And

  In the case of the above-described configuration, in a certain series of voltage measurements, when an odd group voltage is measured first and then an even group voltage is measured, the next series of voltage measurements first includes an even group voltage measurement. Voltage measurement is performed, and then an odd group voltage measurement is performed later. Then, a group that is voltage measured later in a series of voltage measurements is the same as a group that is voltage measured earlier in the next series of voltage measurements. As a result, the sign of the capacitor voltage is not reversed when a series of voltage measurements are completed and the next series of voltage measurements is performed. By doing so, the charging time of the first battery cell in a series of voltage measurements can be shortened.

  According to the present invention, in the method of measuring the voltage of a battery cell by a flying capacitor method, after measuring the voltage of one battery cell, when measuring the voltage of the next battery cell, the capacitor is not discharged, and By making the battery cell measurement sequence in order of voltage magnitude, it is possible to reduce the time required for battery cell voltage measurement by making good use of the electric charge accumulated in the capacitor, and consequently to a plurality of batteries. The time required for a series of voltage measurements on the cell can be reduced.

  According to the second aspect of the present invention, the series of voltages performed first by switching the order of the voltage values when switching the measurement order of the plurality of battery cells in ascending order and descending order for each series of voltage measurements. Since the voltage difference between the last battery cell in the measurement and the first battery cell in the subsequent series of voltage measurements can be reduced, the charging time of the first battery cell in the series of voltage measurements can be shortened.

  According to the third invention, a method of measuring a voltage of a battery cell by a flying capacitor method in which a battery cell having an odd arrangement order and a battery cell having an even arrangement order are connected to a capacitor in a state where the sign is reversed. , After measuring the voltage of one battery cell, when measuring the voltage of the next battery cell, the capacitor is not discharged, and the odd number group of the odd numbered battery cells and the even number order of the battery cells are arranged. By performing voltage measurement separately for even groups of battery cells, it is possible to reduce the time required for voltage measurement of battery cells by making good use of the electric charge accumulated in the capacitor, and consequently to multiple battery cells. The time required for a series of voltage measurements for can be reduced.

  According to the fourth invention, in each of the odd-numbered group and the even-numbered group, the measurement order of the plurality of battery cells in the next series of voltage measurement is rearranged in order of the magnitude of the voltage value, thereby The time required to complete the voltage measurement can be shortened.

  According to the fifth invention, in the next series of voltage measurements, the measurement order of the plurality of battery cells in the group that measures the voltage first is rearranged so that the magnitude of the voltage value is in descending order, while the next series of voltages is measured. By rearranging the measurement order of a plurality of battery cells in a group for voltage measurement later in the measurement so that the magnitude of the voltage value is ascending order, the charging time of the first battery cell in the later group is shortened, and the battery The time required for measuring the voltage of the cell can be shortened.

  According to the sixth invention, each time a series of voltage measurements on a plurality of the battery cells is completed, the first voltage measurement group and the voltage measurement group are switched in order, so that the first voltage measurement in the series of voltage measurements is performed. The charging time of the battery cell can be shortened.

  According to the seventh invention, in the voltage measuring device for measuring the voltage of the battery cell by the flying capacitor method, after measuring the voltage of one battery cell, the capacitor is discharged when measuring the voltage of the next battery cell. And by making the measurement order of the battery cells the order of the voltage magnitude, the time required for the voltage measurement of the battery cells can be shortened by making good use of the charges accumulated in the capacitor, and consequently The time required for a series of voltage measurements for a plurality of battery cells can be reduced.

  According to the eighth aspect of the present invention, the sequence of voltages performed first by switching the order of voltage values when switching the measurement order of the plurality of battery cells between ascending order and descending order for each series of voltage measurements. Since the voltage difference between the last battery cell in the measurement and the first battery cell in the subsequent series of voltage measurements can be reduced, the charging time of the first battery cell in the series of voltage measurements can be shortened.

  According to the ninth aspect of the invention, the voltage for measuring the voltage of the battery cell by the flying capacitor system in which the positive and negative are reversed between the odd-numbered battery cell and the even-numbered battery cell in the arrangement order. In the measuring apparatus, after measuring the voltage of one battery cell, when measuring the voltage of the next battery cell, the capacitor is not discharged and the odd number group of the odd numbered battery cells and the arrangement order are By performing voltage measurement separately for the even group of even-numbered battery cells, it is possible to reduce the time required to measure the voltage of the battery cell by effectively using the charge accumulated in the capacitor. The time required for a series of voltage measurements on the battery cell can be shortened.

  According to the tenth invention, in each of the odd-numbered group and the even-numbered group, the measurement order of the plurality of battery cells in the next series of voltage measurements is rearranged in order of the magnitude of the voltage value. The time required to complete the voltage measurement can be shortened.

  According to the eleventh aspect, the measurement sequence of the plurality of battery cells in the group in which voltage measurement is performed first in the next series of voltage measurement is rearranged so that the magnitude of the voltage value is descending, while the next series of voltage measurement By rearranging the measurement order of a plurality of battery cells in a group for voltage measurement later in the measurement so that the magnitude of the voltage value is ascending order, the charging time of the first battery cell in the later group is shortened, and the battery The time required for measuring the voltage of the cell can be shortened.

  According to the twelfth invention, each time a series of voltage measurements on a plurality of the battery cells is completed, the first voltage measurement group and the voltage measurement group are switched in order, so that the first voltage measurement in the series of voltage measurements is performed. The charging time of the battery cell can be shortened.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Embodiment 1 of the Invention
FIG. 2 is a circuit diagram schematically showing a part of an electric system of a hybrid electric vehicle including a voltage measuring device according to an embodiment of the present invention.

  The hybrid electric vehicle includes an electric motor 11 as a drive source and a plurality of battery cells CL, CL,..., A battery cell unit 2 as a battery that is a power source of the electric motor 11, and the electric motor 11. An inverter 12 interposed between the battery cell unit 2, a voltage measuring device 3 that measures the voltage of the battery cell CL, and an HEV controller 10 that controls the electric motor 11, the inverter 12, and the voltage measuring device 3. I have.

  During the operation of the hybrid electric vehicle, the electric motor 11 is supplied with electric power from the battery cell unit 2 via the inverter 12 and functions as a drive source. On the other hand, during the deceleration of the hybrid electric vehicle, the electric motor 11 functions as a generator and charges the battery cell unit 2 via the inverter 12.

  The HEV controller 10 is configured to switch the drive source between the electric motor 11 and the engine (not shown) according to the running state, and to control the inverter 12 accordingly. The HEV controller 10 also controls a control unit 5 described later of the voltage measuring device 3.

The battery cell unit 2 is configured by connecting a plurality of battery cells CL, CL,... In series. Specifically, the battery cell unit 2 is configured by connecting m battery modules M, M,... Configured by connecting n battery cells CL, CL,. That is, the battery cell unit 2 is configured by connecting N (= n × m) battery cells CL, CL,... In series. When the battery cells CL are referred to by distinguishing the order of arrangement in series connection, one end side of the series connection (upper side in FIGS. 1 and 2) is first, as in “CL ₁ ”, and the series connection after “CL”. Named with a number counted from one end. When the arrangement order of the battery cells CL is not distinguished, it is simply referred to as “CL”. The battery module M is also referred to similarly.

The battery cell unit 2 configured in this way includes a positive electrode of the _first battery cell CL1 located on one end side in series connection, and a negative electrode of the _Nth battery cell CLN located on the other end side in series connection. Is connected to the inverter 12 so that the inverter 12 is connected in parallel.

  In the present embodiment, the number of battery cells CL included in one battery module M is the same for each battery module M, but is not limited thereto.

  The voltage measuring device 3 includes measuring units 4, 4,... Provided for each battery module M, and a control unit 5 connected to the measuring units 4, 4,. Yes.

  FIG. 1 shows a circuit diagram of the measurement unit 4. The measurement unit 4 includes a capacitor C as a so-called flying capacitor, a voltage measurement circuit 45 for measuring the voltage of the capacitor C, a first switch circuit 41 for connecting the capacitor C and each battery cell CL, the capacitor C and a second switch circuit 42 for connecting the voltage measurement circuit 45 to each other.

The first switch circuit 41 functions as a sampling switch, and switches connection and disconnection between the battery cell CL to be measured and the capacitor C from the battery cells CL ₁ ,..., CL _n. . The first switch circuit 41 constitutes a connection circuit. The first switch circuit 41, the battery cell _CL 1, CL _2, ... positive-side connection line _La 1+ one end to the positive electrode is connected to, _{La 2+,} ... and the battery cell _CL 1, CL _2, ... to the negative electrode of The negative electrode side connection lines La ₁₋ , La ₂₋ ,... Connected to one end and the positive electrode side connected to one terminal of the capacitor C while the other ends of the positive electrode side connection lines La ₁₊ , La _{2+ ,.} The other end of the common line La +, the negative electrode side connection lines La ₁₋ , La ₂₋ ,... And the negative electrode side common line La− connected to the other terminal of the capacitor C, and the positive electrode side connection line La ₁₊ , La _2+, ... resistor _R 1+ which is connected in series with _{each, R 2+,} ... and read switches _SWa 1+, _{SWa 2+,} ... and the negative electrode side connection lines _La 1-, _{La 2-,} ... series to each And resistors R ₁₋ , R ₂₋ ,... And read switches SWa ₁₋ , SWa ₂₋ ,.

  Here, the numbers following “La” of the connection line, “SWa” of the read switch, and resistance “R” correspond to the arrangement order of the connected battery cells CL, and the signs “+” and “−” It corresponds to the positive electrode side and the negative electrode side. Only 2n connection lines La and read switches SWa are provided for n battery cells CL, CL,.

Each read switch _SWa 1+ of the first switch circuit 41 having such a structure, _{SWa 1-,} by switching the ... ON / OFF of the battery cell _CL 1, ..., cell to be measured from the CL _n CL is connected to the capacitor C in parallel. For example, when the battery cell CL ₁ and the measurement object, and read switch _SWa 1+, the _{SWa 1-and} ON, other reading switch _SWa 2+, _{SWa 2-,} ... to OFF. Further, for example, when the battery cell CL ₂ and the measurement object, reading switch _SWa 2+, and ON the _{SWa 2-,} other reading switch _SWa 1+, _{SWa 1-,} ... to OFF.

The second switch circuit 42 functions as a transfer switch, and switches connection and disconnection between both terminals of the capacitor C and the two input terminals of the voltage measurement circuit 45. Specifically, a first connection line Lb ₁ that connects one terminal of the capacitor C and one input terminal of the voltage measurement circuit 45, and a first connection line Lb ₁ that connects the other terminal of the capacitor C and the other input terminal of the voltage measurement circuit 45. 2 connection line Lb ₂ , first read switch SWb ₁ provided in the first connection line Lb ₁ , and second read switch SWb ₂ provided in the second connection line Lb ₂ . These first and second read switch _SWb 1, while connecting the capacitor C and the voltage measurement circuit 45 by turning ON the SWb _2, the capacitor C by turning OFF the first and second read switch _SWb 1, SWb ₂ And the voltage measurement circuit 45 are disconnected.

The voltage measurement circuit 45 measures the voltage of the capacitor C and outputs a digital signal corresponding to the voltage. Specifically, the voltage measurement circuit 45 includes an operational amplifier OA and an A / D converter AD. One terminal and the other terminal of the capacitor C are connected to the two input terminals of the operational amplifier OA through connection lines Lb ₁ and Lb ₂ , respectively. The operational amplifier OA constitutes an operational amplifier circuit that amplifies and outputs the voltage of the capacitor C. The A / D converter AD converts the analog signal output from the operational amplifier OA into a digital signal and outputs it. An output terminal of the A / D converter AD that is an output terminal of the voltage measurement circuit 45 is connected to the control unit 5.

  The control unit 5 includes a CPU 51, a ROM 52, a RAM 53, and an I / F (interface) 54. This control unit 5 constitutes a control unit. The CPU 51 executes the control program stored in the ROM 52 and controls each measurement unit 4. The RAM 53 stores temporary data. For example, the measurement result of the voltage of each battery cell CL is stored for each battery cell CL. This RAM 53 constitutes a storage unit. The ROM 52 and RAM 53 may be other storage means. The I / F 54 is connected to the first and second switch circuits 41 and 42 and the voltage measurement circuit 45, and the CPU 51 controls them and acquires the measurement result output from the A / D converter AD. .

The voltage measuring device 3 configured in this way measures and monitors the voltage of each battery cell CL in order to prevent overdischarge and overcharge of each battery cell CL. This voltage measurement is performed for each battery module M, and the voltage measurements in the battery modules M, M,... Are performed in parallel. Further, in this voltage measurement, a series of voltage measurements for all the battery cells CL ₁ ,..., CL _n included in the battery module M is taken as one measurement series, and this measurement series is set at a predetermined interval while the ignition is ON. Repeatedly.

-Voltage measurement operation-
First, the control unit 5 reads the switch operation event stored in the RAM 53 in step Sa1. This switch operation event refers to which read switch SWa ₁₊ , SWa ₁₋ ,... In the first switch circuit 41 is turned ON / OFF in which order, and which read switch is turned ON / OFF. The data defining the combination and the order. This switch operation event is updated every time one measurement series ends, as will be described in detail later. Note that in the first measurement series after the ignition is turned on, the combination and order of the switches SWa and SWa are defined so that the voltage is measured in order from the _first battery cell CL1 according to the arrangement sequence of the series connection.

  Next, in step Sa2, the control unit 5 controls the first switch circuit 41 according to the switch operation event to selectively turn on the designated read switches SWa and SWa, thereby providing one measurement object. The battery cell CL is connected to the capacitor C in parallel. Then, in step Sa3, the control unit 5 charges the capacitor C with the battery cell CL to be measured for a predetermined charging time. Then, the voltage of the capacitor C converges to the voltage of the connected battery cell CL according to the time constants of the first switch circuit 41 and the capacitor C, as indicated by the broken line in FIG. When the charging time elapses, the control unit 5 turns off the switches SWa and SWa in step Sa4. In this way, the control unit 5 fully charges the capacitor C with the battery cell CL to be measured.

  This charging time differs between the first measurement series and the second and subsequent measurement series. The charging time in the first measurement series is a fixed value set in advance. Specifically, the charging time is set to a time that can reliably charge the capacitor C in any battery cell CL under the assumed use conditions. . On the other hand, the charging time in the second and subsequent measurement series is calculated for each battery cell CL. Specifically, in the second and subsequent measurement series, since the voltage of each battery cell CL is known from the previous measurement series, the battery cell CL to be measured and the battery cell CL for which voltage measurement has been completed immediately before Based on the voltage difference in the previous measurement series, the charging time during which the battery cell CL to be measured can be surely fully charged is calculated.

Subsequently, in step Sa5, the control unit 5 controls the second switch circuit 42 to turn on the first and second read switches SWb ₁ and SWb _2, thereby connecting the capacitor C to the voltage measurement circuit 45. . Then, the control unit 5 activates the A / D converter AD in step Sa6. Thus, the control unit 5 reads the analog signal output from the operational amplifier OA and corresponding to the voltage of the capacitor C in a state converted into a digital signal by the A / D converter AD. When the voltage of the capacitor C is read, the control unit 5 controls the second switch circuit 42 in step Sa7 to turn off the first and second read switches SWb ₁ and SWb ₂ to turn off the capacitor C. The connection with the voltage measurement circuit 45 is disconnected.

Thereafter, the control unit 5 reads a memory storage event from the RAM 53 in step Sa8. The memory storage event is an order in which the voltage value measured by the voltage measurement circuit 45 is stored in the memory, that is, data defining a memory address, and is measured in the order according to the switch storage event. by storing the voltage value of CL to a defined memory address, all the battery cells CL _1, ..., when the voltage measurement of the CL _n is completed, n from the first voltage value of the battery cells CL ₁ in memory th voltage of the battery cell CL _n is intended to be aligned as the arrangement order. In step Sa9, the control unit 5 stores the measured voltage value at the memory address indicated by the memory storage event.

Thus, when the voltage measurement for one battery cell CL to be measured is completed, the control unit 5 completes the voltage measurement for all the battery cells CL ₁ ,..., CL _n in the battery module M in step Sa10. Determine whether or not. All the battery cells _CL 1, ..., when the voltage measurement of the CL _n has been completed, the process proceeds to step Sa11, all the battery cells _CL 1, ..., when the voltage measurement of the CL _n is not completed, Returning to step Sa1, voltage measurement of battery cells CL, CL,. At that time, the capacitor C is connected to the next battery cell CL without being discharged.

When the voltage measurement for all the battery cells CL, CL,... In the battery module M is completed, the control unit 5 determines the battery cell CL ₁ defined by the switch operation event stored in the RAM 53 in step Sa11. , ..., it determines the measurement order of CL _n is whether lined on the magnitude of the forward voltage value (ascending or descending does not matter). Specifically, it is determined whether or not the measurement order of the battery cells CL ₁ ,..., CL _n defined by the switch operation event is an arrangement order of series connection. That is, in the first measurement series, the measurement order specified by the switch operation event is in the arrangement order, whereas in the second and subsequent measurement series, the measurement order specified by the switch operation event is in the arrangement order. The order is irrelevant. Therefore, if the measurement order specified by the switch operation event is the arrangement order, the measurement order is not arranged in the order of the voltage value, and the measurement order specified by the switch operation event is the arrangement order. Otherwise, it can be determined that the measurement order is arranged in the order of the magnitude of the voltage value. Alternatively, the determination may be made based on actually measured voltage values depending on whether they are arranged in order of magnitude.

When the measurement order defined by the switch operation event is not arranged in the order of the voltage value of the battery cell CL, the control unit 5 sets the battery cell CL so that the voltage value is in descending order. _1, ..., arrayed CL _n (step Sa13), the switch operation event so as to correspond thereto, and updates rearranges memory storage event (step Sa15). For example, the battery cells _CL 1 voltage value are arranged such that the descending ..., cell _CL 1 in the order of CL _n, ..., as the voltage measurement of the CL _n is performed, the switch _SWa 1+, _{SWa 1-} ,... Are updated as switch operation events. Further, when voltage measurement is performed according to the updated switch operation event, the voltage values measured in descending order of magnitude are stored in the memory in the order of arrangement of the first to nth battery cells CL. The memory address for storing each voltage value specified in (1) is updated as a memory storage event. Steps Sa13 and Sa14 are performed in the first voltage measurement after the ignition is turned on.

On the other hand, when the measurement order specified by the switch operation event is arranged in the order of the voltage value of the battery cell CL, the control unit 5 determines that the measurement order is the magnitude of the voltage value in step Sa12. It is determined whether or not is an ascending order. When the voltage values are arranged in ascending order, the control unit 5 determines in step Sa13 that the voltage values are in descending order based on the measured voltage values. ₁ ,..., CL _n are arranged, and the switch operation event and the memory storage event are rearranged and updated so as to correspond to them (step Sa15). On the other hand, when the voltage values are arranged in descending order, the control unit 5 determines in step Sa14 the battery cells CL, CL, so that the voltage values are in ascending order based on the measured voltage values. Are arranged, and the switch operation event and the memory storage event are rearranged and updated so as to correspond to them (step Sa15). The method of updating these switch operation events and memory storage events is as described above.

Thus, after the voltage measurement for all the battery cells CL ₁ ,..., CL _n in the battery module M is completed, the control unit 5 updates the switch operation event and the memory storage event based on the voltage value. The next measurement series is performed based on the updated switch operation event and memory storage event.

When voltage measurement is performed based on such a flowchart, the voltage of the capacitor C changes as shown in FIG. In this example, eight battery cells CL ₁ ,..., CL ₈ are provided in the battery module M, and a series of voltage measurements (measurement series) for the _eight battery cells CL ₁ ,. Done. In the figure, the reference numerals in circles indicate the voltage of the capacitors C when the capacitors C are connected to the battery cells CL in the arrangement order corresponding to the numbers.

That is, in the first measurement series (“measurement first” in the figure), the voltages of the battery cells CL ₁ ,..., CL ₈ are measured in the order of arrangement in series connection. Here, since the voltage of each battery cell CL differs slightly, the voltage of the capacitor | condenser C fluctuates up and down for every voltage measurement.

  At this time, when the voltage measurement of a certain battery cell CL is completed and the voltage measurement of the next battery cell CL is performed, the next battery cell CL is connected to the next battery cell CL without discharging the capacitor C. The capacitor C connected to CL retains the charge when the voltage of the previous battery cell CL is measured. As a result, the amount that the capacitor C should be charged in the next battery cell CL depends on the voltage of the previous battery cell CL. That is, when the difference between the voltage of the previous battery cell CL and the voltage of the next battery cell CL is large, the amount of charge to be charged is increased, while the voltage of the previous battery cell CL and the voltage of the next battery cell CL are increased. When the difference from the voltage is small, the amount of charge to be charged is reduced. Depending on the magnitude relationship between the voltage of the previous battery cell CL and the next battery cell CL, the voltage of the capacitor C may be higher than the voltage of the battery cell CL to be connected. To the battery cell CL.

Here, the actual voltage of the capacitor C does not change as shown by the solid line in the figure, and as shown by the broken line, the connected battery cells are connected based on the time constants of the first switch circuit 41 and the capacitor C. It converges to the voltage of CL. The amount of charge to be charged affects the time until the voltage of the capacitor C converges to the voltage of the battery cell CL. In detail, when the amount of charge should be charged is large, that is, when the difference between the voltage of the previous battery cell CL and the voltage of the next battery cell CL is large, the time until the voltage of the capacitor C converges increases. When the amount of charge to be charged is small, that is, when the difference between the voltage of the previous battery cell CL and the voltage of the next battery cell CL is small, the time until the voltage of the capacitor C converges is shortened. For example, when measuring the voltage of the third battery cell CL ₃ or the sixth battery cell CL _{6 having} a large voltage difference from the previous battery cell CL, the voltage of the capacitor C becomes the voltage of the battery cell CL. It takes a long time to converge.

  And the voltage difference between the battery cells CL and CL measured continuously, that is, the adjacent battery cells CL and CL in series connection, is different, and there are some having a large voltage difference, and the voltage difference is small. There are also things. Therefore, when the voltages of the battery cells CL, CL,... Are measured in the order of arrangement, the time until the voltage of the capacitor C converges for each battery cell CL varies. However, as described above, the charging time of the first measurement series is set as a fixed value, which is enough time for the capacitor C to be fully charged, so even if the battery cell CL has a long convergence time, The capacitor C can be fully charged reliably. However, even if the battery cell CL has a short convergence time, it is charged with the same charging time. Therefore, even if the charging time is appropriate for one battery cell CL, the charging time is too long for another battery cell CL. Thus, the time required for voltage measurement is unnecessarily long, and the time for the entire measurement series is also long.

On the other hand, in the second and subsequent measurement series, the measurement order of the battery cells CL ₁ ,..., CL ₈ is rearranged in the order of the measurement voltage value in the previous measurement series. For example, in FIG. 4B, in the second measurement series, the measurement order of the battery cells CL ₁ ,..., CL ₈ is arranged so that the measurement voltage values in the first measurement series are in ascending order. Be replaced. And since the voltage of each battery cell CL does not change so much between the first measurement series and the second measurement series, as a result of performing the second measurement series according to the above-described measurement order, the measured voltages are aligned. As it changed, it gradually grows. That is, in the second measurement series, the battery cells CL ₁ ,..., CL ₈ are measured in the order in which the measured voltage values are actually in ascending order.

As described above, when the voltage measurement of the battery cells CL ₁ ,..., CL ₈ is performed in the order of the voltage value, the voltage is continuously measured as shown in “second measurement” in FIG. The voltage difference between the battery cells CL and CL becomes smaller. If the voltage difference between the battery cells CL and CL whose voltages are continuously measured is small, as described above, the voltage convergence time of the capacitor C is measured when the voltage of the subsequent battery cells CL is measured. Becomes shorter.

In addition, the charging time of the second and subsequent measurement series is calculated based on the difference in the measured voltage value in the previous measurement series between the battery cell CL to be measured and the previous battery cell CL. That is, when the difference in the measured voltage value in the previous measurement series between the battery cell CL to be measured and the previous battery cell CL is small, the voltage difference between the battery cells CL and CL in the current measurement also. Therefore, if the difference is large, the voltage difference between the two battery cells CL and CL should be large in this measurement as well. Charging time is set. That is, when the voltage measurement of the battery cells CL ₁ ,..., CL ₈ is performed in the order of the voltage value, the voltage difference between the battery cells CL and CL that are continuously voltage-measured becomes small. Charging time is shortened. As a result, the time required for the measurement series can be greatly reduced as compared with the configuration in which voltage measurement is performed in the arrangement order in the second and subsequent times shown in FIG.

  The charging time in the second and subsequent measurement series may be set to a fixed value. Even in that case, since the time until the voltage of the capacitor C converges to the voltage of each battery cell CL is short, the charging time in the second and subsequent measurement series is longer than the charging time in the first measurement series. Can be set to a short time, and the time required to measure the voltage of the battery cell CL can be shortened.

Subsequently, in the third measurement series, the measurement order of the battery cells CL ₁ ,..., CL ₈ is rearranged in the order of the measurement voltage values in the second measurement series. Unlike the measurement series, the measurement order is rearranged so that the magnitude of the measurement voltage value is in descending order. As a result, in the third measurement series, the battery cells CL ₁ ,..., CL ₈ are measured in the order in which the measured voltage values are actually in descending order.

Thus, the measurement order of the voltage measurement, the magnitude of the voltage of the battery cell CL _1, ..., a sequence such as the magnitude of the voltage value of CL ₈ is in ascending order, the battery cell CL _1, ..., CL ₈ Are alternately switched for each measurement series in order of decreasing descending order, whereby the voltage of the battery cell CL measured at the end of the previous measurement series and the battery measured at the beginning of the subsequent measurement series in the continuous measurement series Since the difference from the voltage of the cell CL can be reduced, the time required for the voltage measurement of the battery cell CL measured at the beginning of the subsequent measurement series can be shortened.

For example, as shown in FIGS. 4C and 4D, the measurement order is such that the magnitudes of the voltage values are always in ascending order or descending order without switching the order of the voltage values between ascending order and descending order. In the configuration in which the measurement order is rearranged, in a continuous measurement series, the difference between the voltage of the battery cell CL measured at the end of the previous measurement series and the voltage of the battery cell CL measured at the beginning of the subsequent measurement series becomes large. For this reason, the time required for voltage measurement of the first battery cell CL in the later measurement series becomes long. Specifically, in the configuration shown in FIG. 4C in which the measurement order is rearranged so that the magnitude of the voltage value is always in ascending order, the last battery cell CL of the second measurement series is the battery cell CL _1. , ..., a sixth battery cell CL ₆ highest voltage among CL _8. On the other hand, the first battery cell CL of the third measurement series the subsequent battery cells CL _1, ..., most voltage is lower second battery cell CL ₂ in CL _8. In the case of the configuration shown in FIG. 4D in which the measurement order is rearranged so that the magnitude of the voltage value is always in descending order, the last battery cell CL in the second measurement series is the battery cell CL ₁ ,. most voltage is lower second battery cell CL ₂ in CL _8. On the other hand, the first battery cell CL of the third measurement series the subsequent battery cells CL _1, ..., a sixth battery cell CL ₆ highest voltage among CL _8. As described above, when the measurement order is rearranged so that the magnitude of the voltage value is always in ascending or descending order, the voltage of the battery cell CL measured at the end of the previous measurement series and the first of the subsequent measurement series the difference between the voltages of the battery cells CL to be measured battery cell CL _1, ..., becomes largest becomes combined in the CL ₈ in. As a result, the time required to measure the voltage of the battery cell CL to be measured at the beginning of the later measurement series becomes long.

In contrast, for example, as shown in FIG. 4 (B), the measurement order of the voltage measurement, the battery cell CL _1, ..., a sequence such as the magnitude of the voltage value of CL ₈ is in ascending order, the battery cell CL _1, ..., in a configuration in which the magnitude of the voltage value of CL ₈ switches alternately and arrangement such that descending for each measurement series, the voltage is measured at the measurement order as the magnitude of the voltage value becomes ascending Both the last battery cell CL of the second measurement series and the first battery cell CL of the third measurement series that performs voltage measurement in a measurement order in which the magnitude of the voltage value is descending are both battery cells CL ₁ , ..., a sixth battery cell CL ₆ highest voltage among CL _8. Incidentally, omitted illustrated, both the third first battery cell CL of the last cell CL and the fourth measurement series of measurement series, the battery cell CL _1, ..., the most voltage in CL ₈ the lower second battery cell CL _2. Thus, in the case of a configuration in which the measurement order of voltage measurement is alternately switched for each measurement series, the order in which the magnitude of the voltage value is in ascending order and the order in which the magnitude of the voltage value is in descending order, the voltage of the battery cell CL to end the measurement of the previous measurement series, the difference is the battery cell CL 1 of the first measuring voltage of the battery cell CL of measurement series _after, ..., smallest combined in the CL ₈ It becomes. As a result, the amount of charge accumulated in the capacitor C in the last voltage measurement of the previous measurement series and the amount of charge accumulated in the capacitor C in the first voltage measurement of the subsequent measurement series are almost the same. In the first voltage measurement of the measurement series, the voltage required for the voltage measurement can be shortened by quickly converging the voltage of the capacitor C to the voltage of the battery cell CL.

  As shown in FIGS. 4C and 4D, the measurement order is always set so that the magnitude of the voltage value is in ascending order or descending order without switching the order of the magnitude of the voltage value between ascending order and descending order. Even if it is a configuration to rearrange, the voltage measurement of the first battery cell in the measurement series takes time, but the voltage measurement of other battery cells in the measurement series can shorten the measurement time as described above. it can. Further, as in the second embodiment described later, a circuit for discharging the voltage of the capacitor C may be provided so that the voltage of the capacitor C is discharged between successive measurement series. By carrying out like this, the time at the time of charging the first battery cell CL of a later measurement series can be shortened.

Therefore, according to this embodiment, after the second measurement series, by measuring the voltage of the battery cells CL ₁ ,..., CL ₈ in the order of the voltage value, the capacitor C is the measurement target battery. It is possible to reduce the amount of charge to be charged and discharged to the capacitor C when connected to the cell CL, and to quickly converge the voltage of the capacitor C to the voltage of the battery cell CL. As a result, the time required for voltage measurement of the battery cell CL can be shortened, and as a result, the time required for the measurement series can be shortened.

  In addition, since the charging time is predicted and set based on the measured voltage value in the previous measurement series, as described above, the voltage of the capacitor C is quickly converged to the voltage of the battery cell CL. The charging time can be set to a necessary and sufficient time for each voltage measurement. By carrying out like this, according to each voltage measurement, charging time can be set flexibly and the voltage measurement of the battery cell CL can be shortened as much as possible.

In addition, the measurement order of the battery cells CL ₁ ,..., CL ₈ is alternately arranged for each measurement series in an arrangement in which the magnitude of the voltage value is in ascending order and an arrangement in which the magnitude of the voltage value is in descending order. Since the voltage difference between the last battery cell CL of the previous measurement series and the first battery cell CL of the subsequent measurement series can be reduced by switching, the voltage of the first battery cell CL of the subsequent measurement series can be reduced. In the measurement, the voltage required for the voltage measurement can be shortened by quickly converging the voltage of the capacitor C to the voltage of the battery cell CL.

<< Embodiment 2 of the Invention >>
Subsequently, Embodiment 2 of the present invention will be described. The voltage measurement apparatus 203 according to the second embodiment is different from the first embodiment in the configuration of the measurement unit 204. Therefore, the same configurations as those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted, and different portions will be mainly described.

  FIG. 5 shows a circuit diagram of a part of an electric system of a hybrid vehicle equipped with the voltage measuring device 203 according to the second embodiment, and FIG. 6 shows a circuit diagram of the measuring unit 204.

  The measurement unit 204 includes a capacitor C as a so-called flying capacitor, a voltage measurement circuit 45 for measuring the voltage of the capacitor C, a first switch circuit 41 for connecting the capacitor C and each battery cell CL, the capacitor A second switch circuit 42 for connecting C and the voltage measurement circuit 45 and a third switch circuit 43 for discharging the capacitor C are provided. The configuration of the voltage measurement circuit 45 is the same as that of the first embodiment.

The first switch circuit 41 functions as a sampling switch, and switches connection and disconnection between the battery cell CL to be measured and the capacitor C from the battery cells CL ₁ ,..., CL _n. . The first switch circuit 41 constitutes a connection circuit. The first switch circuit 41 has an odd-side connection line La whose one end is connected to the positive electrodes of the odd-numbered battery cells CL ₁ , CL ₃ ,... (Or the negative electrodes of the even-numbered battery cells CL ₂ , CL ₄ ,. ₁ , La ₃ ,..., And even-numbered connection lines La having one ends connected to the positive electrodes of the even-numbered battery cells CL ₂ , CL ₄ ,... (Or the negative electrodes of odd-numbered battery cells CL ₁ , CL ₃ ,. ₂ , La ₄ ,..., And the other ends of the odd-numbered connection lines La ₁ , La ₃ ,... Are connected to the odd-numbered common line La + connected to one terminal of the capacitor C and the even-numbered connection lines La ₂ , The other end of La ₄ ,... Is connected and the other side common line La− is connected to the other terminal of the capacitor C, the odd side connection lines La ₁ , La ₃ ,... And the even side connection lines La ₂ , La _4. For each of ... There are resistors R ₁ , R ₂ ,... And read switches SWa ₁ , SWa ₂ ,.

Here, the subscript following “La” in the connection line, “SWa” in the read switch, and resistance “R” corresponds to the subscript of the battery cell CL to which the positive electrode is connected. Note that the connection line, the read switch, and the resistor connected to the negative electrode of the _nth battery cell CLn are referred to as “La _{n + 1} ”, “SWa _{n + 1} ”, and “R _{n + 1} ”, respectively. That is, only n + 1 connection lines La, read switches SWa, and resistors R are provided for n battery cells CL, CL,.

Each read switch _SWa 1, SWa ₂ of the first switch circuit 41 thus configured, by switching a ... ON / OFF of the battery cell _CL 1, ..., cell be measured from the CL _n CL Are connected in parallel to the capacitor C. For example, when the battery cell CL ₁ and the measurement object, and the read switches _SWa 1, SWa ₂ and ON, other reading switch _SWa 3, SWa _4, the ... to OFF. Further, for example, when the battery cell CL ₂ and the measurement object, and the read switches _SWa 2, SWa ₃ and ON, other read switches _SWa 1, SWa _4, the ... to OFF.

The second switch circuit 42 functions as a transfer switch, and switches connection and disconnection between both terminals of the capacitor C and the two input terminals of the voltage measurement circuit 45. Specifically, a first connection line Lb ₁ that connects one terminal of the capacitor C and one input terminal of the voltage measurement circuit 45, a first read switch SWb ₁ provided in the first connection line Lb ₁ , The second connection line Lb ₂ branched from the capacitor C side of the first readout line SWb _{1 of} the first connection line Lb ₁ and connected to the other input terminal of the voltage measurement circuit 45, and the second connection line Lb ₂ a second read switch SWb ₂ that is provided, while the end connected to the other terminal of the capacitor C, the other end to the voltage measurement circuit 45 side than the first read switch SWb ₁ of the first connection line Lb ₁ a third connection line Lb ₃ which is connected, a third read switch SWb ₃ provided on the third connection line Lb _3, capacitor than the third read switch SWb ₃ of the third connection line Lb ₃ A fourth connection line Lb ₄ than the second read switch SWb ₂ of the second connection line Lb ₂ branches from the side is connected to the voltage measuring circuit 45 side, the provided fourth connection line Lb ₄ 4 and a read-out switch SWb _4. The second switch circuit 42 turns on the first and fourth readout switches SWb ₁ and SWb ₄ and turns off the second and third readout switches SWb ₂ and SWb ₃ , thereby connecting one terminal of the capacitor C. The other terminal of the capacitor C is connected to one input terminal of the voltage measurement circuit 45 and the other input terminal of the voltage measurement circuit 45. On the other hand, the second switch circuit 42 turns on the second and third readout switches SWb ₂ and SWb ₃ and turns off the first and fourth readout switches SWb ₁ and SWb ₄ , thereby connecting one terminal of the capacitor C to a voltage. The other terminal of the capacitor C is connected to the other input terminal of the measurement circuit 45 and one input terminal of the voltage measurement circuit 45. Further, the second switch circuit 42 disconnects the connection between the capacitor C and the voltage measurement circuit 45 by turning off the _first to fourth readout switches SWb _{1 to} SWb ₄ .

The third switch circuit 43 functions as a reset switch and switches connection and disconnection of both terminals of the capacitor C. Specifically, the third switch circuit 43 has one end connected to the capacitor C side from the branch point of the first connection line Lb ₁ and the second connection line Lb _2, and the other end connected to the third connection line Lb ₃ . It has a connection line Lc connected to the capacitor C side from a branch point with the fourth connection line Lb _4, and a reset switch SWc and a discharge resistor R provided in the connection line Lc. By turning on the reset switch SWc, both terminals of the capacitor C are connected, and by turning off the reset switch SWc, the connection between both terminals of the capacitor C is disconnected.

The voltage measuring operation of the voltage measuring apparatus 203 configured as described above will be described below with reference to the flowchart of FIG. The voltage measurement by the voltage measuring device 203 is performed for each battery module M, and the voltage measurements in the battery modules M, M,... Are performed in parallel. Further, in this voltage measurement, a series of voltage measurements for all the battery cells CL ₁ ,..., CL _n included in the battery module M is taken as one measurement series, and this measurement series is set at a predetermined interval while the ignition is ON. Repeatedly.

-Voltage measurement operation-
First, the control unit 5 reads the switch operation event stored in the RAM 53 in step Sb1. This switch operation event refers to which of the read switches SWa ₁ , SWa ₂ ,... In the first switch circuit 41 is to be turned ON / OFF and in what order the read switches SWa and SWa to be turned ON. Combination and order of the combinations, and the combination of readout switches SWb and SWb to be turned on, which readout switch among the readout switches SWb _{1 to} SWb ₄ in the second switch circuit 42 is turned on and in what order, and This data defines the order. This switch operation event is updated every time one measurement series ends, as will be described in detail later.

Switch operation event in the present embodiment, the battery cells _CL 1 of the odd-numbered battery cells _CL 1 -CL _n is the arrangement order in the series connection, CL _3, an odd group of ..., the even-numbered battery cells _CL 2, CL ₄ are grouped into even-numbered groups, and voltage measurement is first performed on battery cells CL, CL,... Belonging to one of the odd-numbered group and even-numbered group, and then, the batteries belonging to the other group. The combination of read switches SWa and SWa to be turned on and the order thereof and the combination of read switches SWb and SWb to be turned on and the order thereof are defined so as to measure the voltages of the cells CL, CL,. In addition, in the switch operation event in the first measurement series after the ignition is turned on, first, voltage reading is performed for the battery cells in the odd group, and then the read switches SWa, The combination of SWa and its order and the combination and order of readout switches SWb and SWb to be turned on are defined.

  Next, in step Sb2, the control unit 5 controls the first switch circuit 41 according to the switch operation event to selectively turn on the designated read switches SWa and SWa, thereby one battery to be measured. Cell CL is connected to capacitor C in parallel. In step Sb3, the control unit 5 charges the capacitor C with the battery cell CL as a measurement target for a predetermined charging time. Then, the voltage of the capacitor C converges to the voltage of the connected battery cell CL in accordance with the time constants of the first switch circuit 41 and the capacitor C, as indicated by the broken line in FIG. When the charging time has elapsed, the control unit 5 turns off the switches SWa and SWa in step Sb4. In this way, the control unit 5 fully charges the capacitor C with the battery cell CL to be measured.

  The charging time is set in the same manner as in the first embodiment, and is different between the first measurement series and the second and subsequent measurement series.

  Subsequently, in step Sb5, the control unit 5 controls the second switch circuit 42 in accordance with the switch operation event to selectively turn on the designated readout switches SWb and SWb, thereby causing the capacitor C to become a voltage measurement circuit. 45.

Specifically, when measuring the voltages of the odd-numbered battery cells CL ₁ , CL ₃ ,..., The first and fourth read switches SWb ₁ , SWb ₄ are turned on while the even-numbered battery cells CL ₂ are arranged. , CL ₄ ,... Are measured, the second and third readout switches SWb ₂ , SWb ₃ are turned on. In the present embodiment, since the connection line La between the adjacent battery cells CL and CL is shared in series connection, when the capacitor C is charged with the odd-numbered battery cells CL ₁ , CL ₃ ,. The sign of the voltage applied to the capacitor C differs from when the capacitor C is charged with the battery cells CL ₂ , CL ₄ ,. Therefore, when the capacitor C is charged with the odd-numbered battery cells CL ₁ , CL ₃ ,... In order to align the signs of the voltage values measured by the voltage measurement circuit 45, and even-numbered battery cells CL ₂ , CL _4. The capacitor C is connected to the voltage measuring circuit 45 by switching the read switches SWb and SWb that are selectively turned on when the capacitor C is charged with. By doing so, the sign of the voltage of the capacitor C measured by the voltage measurement circuit 45 is aligned (for example, positive) for any battery cell CL.

  Then, in step Sb6, the control unit 5 activates the A / D converter AD. Thus, the control unit 5 reads the analog signal output from the operational amplifier OA and corresponding to the voltage of the capacitor C in a state converted into a digital signal by the A / D converter AD. When the control unit 5 reads the voltage of the capacitor C, in step Sb7, the control unit 5 controls the second switch circuit 42 according to the switch operation event to turn off the designated read switches SWb and SWb, thereby turning off the capacitor C. And the voltage measurement circuit 45 are disconnected.

  Thereafter, the control unit 5 reads a memory storage event from the RAM 53 in step Sb8. This memory storage event is the same as in the first embodiment, and is data that defines the order in which the voltage values measured by the voltage measurement circuit 45 are stored in the memory, that is, the memory addresses. In step Sb9, the control unit 5 stores the measured voltage value at the memory address indicated by the memory storage event.

Thus, when the voltage measurement for one battery cell CL to be measured is completed, the control unit 5 completes the voltage measurement for all the battery cells CL ₁ ,..., CL _n in the battery module M in step Sb10. Determine whether or not. All the battery cells _CL 1, ..., when the voltage measurement of the CL _n has been completed, the process proceeds to step Sb11, all the battery cells _CL 1, ..., when the voltage measurement of the CL _n is not completed, Returning to step Sb1, voltage measurement of the uncompleted battery cells CL, CL,... Is performed according to the above procedure. At that time, the capacitor C is connected to the next battery cell CL without being discharged.

  Then, when the voltage measurement for all the battery cells CL, CL,... In the battery module M is completed, the control unit 5 determines that the odd group and the even number defined by the switch operation event stored in the RAM 53 in step Sb11. Swap the order with the group.

  Thereafter, in step Sb12, the control unit 5 is replaced in step Sb11. As a result, the current measurement voltage values of the battery cells CL, CL,... Belonging to the group in which voltage measurement is performed first in the next measurement series are in descending order. On the other hand, the battery cells CL, CL,... Belonging to a group in which voltage measurement will be performed later in the next measurement series are arranged so that the current measurement voltage values are in ascending order. Then, the control unit 5 updates the switch operation event and the memory storage event so as to correspond to the arranged battery cells CL, CL,... (Step Sb13).

Thus, after the voltage measurement for all the battery cells CL ₁ ,..., CL _n in the battery module M is completed, the control unit 5 updates the switch operation event and the memory storage event based on the voltage value. In the next measurement series, the measurement is performed based on the updated switch operation event and memory storage event.

When voltage measurement is performed based on such a flowchart, the voltage of the capacitor C changes as shown in FIG. In this example, eight battery cells CL ₁ ,..., CL ₈ are provided in the battery module M, and a series of voltage measurements (measurement series) for the _eight battery cells CL ₁ ,. Done. In the figure, the reference numerals in circles indicate the voltage of the capacitors C when the capacitors C are connected to the battery cells CL in the arrangement order corresponding to the numbers.

That is, in the first measurement series ("measurement first time" in the figure), first, the voltage measurement of the battery cells in the odd group is performed, and then the voltage measurement of the battery cells in the even group is performed. As described above, in the configuration of the present embodiment, the odd-numbered battery cells CL ₁ , CL ₃ ,... And the even-numbered battery cells CL ₂ , CL ₄ ,. That is, as shown in FIG. 8, when the voltage of the capacitor C when the capacitor C is charged by the odd-numbered battery cells CL ₁ , CL ₃ ,... Is positive, the even-numbered battery cells CL ₂ , CL ₄ ,. When the capacitor C is charged in..., The voltage of the capacitor C becomes negative. However, in these, the voltage of the battery cells CL, CL,... Only appears as positive or negative as the voltage of the capacitor C, and the sign of the voltage of the battery cells CL, CL,. I don't mean. That is, the voltages of the battery cells CL, CL,... Are always positive, and the voltages of the even-numbered groups of battery cells CL ₂ , CL ₄ ,. Further, the voltage measured by the voltage measuring circuit 45 is also measured by switching the second switch circuit 42 so that the voltages of the even-numbered battery cells CL ₂ , CL ₄ ,... Is done.

  In this way, the battery cells CL, CL,... Are grouped into an odd group and an even group based on the arrangement order, and voltage measurement is first performed on the battery cells CL, CL,. By measuring the voltages of the battery cells CL, CL,... Belonging to the other group, the voltage applied to the capacitor C is positive and the voltage applied to the capacitor C is negative. Voltage measurement can be performed separately for the cells CL, CL,... As a result, the time required for voltage measurement can be shortened.

  That is, when the voltage applied to the capacitor C is switched between positive and negative for each voltage measurement, the amount of charge to be charged / discharged to the capacitor C is very large, so that the voltage of the capacitor C is extremely converged. Takes a long time. On the other hand, by performing voltage measurement for each of the battery cells CL, CL,. The charging time can be shortened. As a result, the time required for voltage measurement can be shortened. Note that when the group for voltage measurement is switched, that is, when the sign of the voltage applied to the capacitor C is switched, the control unit 5 controls the third switch circuit 43 to turn on the reset switch, thereby switching the capacitor. C is discharged. In this way, when the sign of the voltage applied to the capacitor C is switched, the charge accumulated in the capacitor C is once made zero, and the charging of the next capacitor C is completed as soon as possible, and the first switch circuit 41 and the capacitor C are prevented from flowing.

  In the second and subsequent measurement series, the order of the groups for voltage measurement is switched first. For example, in FIG. 8B, in the first measurement series, the odd group voltage measurement is performed first, and then the even group voltage measurement is performed, whereas in the second measurement series, the even group group measurement is performed first. A voltage measurement is performed, and an odd group voltage measurement is performed later. Further, in the third measurement series, the voltage measurement of the odd group is performed first, and the voltage measurement of the even group is performed later. By doing so, the sign of the voltage applied to the capacitor C at the time of voltage measurement becomes the same when a certain measurement series ends and shifts to the next measurement series. That is, since it is not necessary to discharge the capacitor C when the measurement series is switched, the time when the measurement series is switched and the time required for the voltage measurement of the first battery cell CL after the measurement series is switched can be shortened. .

  In the second and subsequent measurement series, the measurement order of the battery cells CL, CL,... In each group is rearranged in the order of the measurement voltage value in the previous measurement series. By doing so, the voltage of the capacitor C at the time of measuring the voltage of the battery cell CL subsequent to the second and subsequent times shown in FIG. The convergence time can be shortened, and the time required for the measurement series can be greatly shortened.

  However, in the present embodiment, in the group in which the voltage is measured first, the measurement order of the battery cells CL, CL,... Is rearranged so that the magnitude of the measurement voltage value in the previous measurement series is in descending order. In a group in which voltage is measured later, the measurement order of the battery cells CL, CL,... Is rearranged so that the measurement voltage values in the previous measurement series are in ascending order. By doing so, the difference between the voltage of the capacitor C when measuring the voltage of the last battery cell CL of the previous group and the voltage of the capacitor C when measuring the voltage of the first battery cell CL of the subsequent group is reduced. The time for discharging the capacitor C by the third switch circuit 43 and the time for charging the capacitor C by the battery cell CL can be shortened.

  In other words, the measurement order of the battery cells CL, CL,... In the previous group is set in ascending order, and the measurement order of the battery cells CL, CL,. When rearranged in descending order, the battery cell CL measured at the end of the previous group becomes the battery cell CL with the highest voltage in the group, while the battery cell CL measured at the beginning of the subsequent group The battery cell CL has the highest voltage in the group. As a result, when the previous group and the subsequent group are switched, the time for discharging the capacitor C by the third switch circuit is increased, and the charging time for charging the first battery cell CL of the subsequent group is also increased. . On the other hand, the measurement order of the battery cells CL, CL,... In the subsequent group is set to the magnitude of the voltage value so that the measurement order of the battery cells CL, CL,. When the battery cells CL are rearranged in ascending order, the battery cell CL measured at the end of the previous group becomes the battery cell CL having the lowest voltage in the group, while the battery cell CL measured at the beginning of the subsequent group. Becomes the battery cell CL having the lowest voltage in the group. As a result, as described above, the time for discharging the capacitor C by the third switch circuit 43 and the time for charging the capacitor C by the battery cell CL can be shortened.

Therefore, according to the second embodiment, the capacitor C is in a state where the positive and negative are inverted between the odd-numbered battery cells CL ₁ , CL ₃ ,... And the even-numbered battery cells CL ₂ , CL ₄ ,. In the configuration in which the voltage of the battery cell CL is measured by the flying capacitor method connected to the capacitor C, after measuring the voltage of one battery cell CL, the capacitor C is not discharged when measuring the voltage of the next battery cell CL. In addition, by performing voltage measurement separately on the odd-numbered battery cells CL ₁ , CL ₃ ,... Of the odd-numbered battery cells and the even-numbered groups of battery cells CL ₂ , CL ₄ ,. The time required for the voltage measurement of the battery cell CL can be shortened by making good use of the electric charge accumulated in the capacitor C, and thus the time required for the measurement series can be shortened. it can.

  In addition, by switching the group that performs voltage measurement first and the group that performs voltage measurement later for each measurement series, a voltage applied to the capacitor C by the battery cell CL that performs voltage measurement at the end of a certain measurement series; Since the sign of the voltage applied to the capacitor C is the same by the battery cell CL that performs voltage measurement at the beginning of the subsequent measurement series, it is not necessary to discharge the capacitor C when the measurement series is switched, and the measurement series is switched. Time and the time required for the voltage measurement of the first battery cell CL after the measurement series is switched can be shortened.

  Further, after the second measurement series, by measuring the voltage of the battery cells CL, CL,... In the order of the voltage value in each group, the capacitor C is connected to the battery cell CL to be measured. In this case, the amount of charge to be charged / discharged in the capacitor C can be reduced, and the voltage of the capacitor C can be quickly converged to the voltage of the battery cell CL. As a result, the time required for voltage measurement of the battery cell CL can be shortened, and as a result, the time required for the measurement series can be shortened.

  In addition, since the charging time is predicted and set based on the measured voltage value in the previous measurement series, as described above, the voltage of the capacitor C is quickly converged to the voltage of the battery cell CL. The charging time can be set to a necessary and sufficient time for each voltage measurement. By carrying out like this, according to each voltage measurement, charging time can be set flexibly and the voltage measurement of the battery cell CL can be shortened as much as possible.

  Further, in one measurement series, the measurement order of the battery cells CL, CL,... Of the group measured first is changed to the battery cells CL, CL of the group measured later so that the magnitude of the voltage value is descending. ,... Are rearranged so that the magnitudes of the voltage values are in ascending order, whereby the time for discharging the capacitor C by the third switch circuit 43 when the previous group and the subsequent group are switched, and The time for charging the capacitor C with the first battery cell CL of the later group can be shortened.

  Furthermore, the group that performs voltage measurement first and the group that performs voltage measurement later are switched for each measurement series, and the measurement order of the battery cells CL, CL,... The voltage measurement is performed at the end of a certain measurement series by rearranging the measurement order of the battery cells CL, CL,... Of the group measured later so that the magnitude of the voltage value is ascending order. When the measurement series is switched between the battery cell CL performing the measurement and the battery cell CL performing the voltage measurement at the beginning of the subsequent measurement series because the sign of the voltage applied to the capacitor C is the same and the voltage difference is also reduced. And the time required for voltage measurement of the first battery cell CL after the measurement series is switched can be shortened.

  In the second embodiment, the measurement unit 204 is provided with the third switch circuit, but may be omitted. In such a configuration, the capacitor C is not discharged when the odd group and the even group are switched.

  In addition, the above embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or its use.

  As described above, the present invention is useful for a battery cell control device and a control method for measuring the voltage of a battery cell in a plurality of battery cells connected in series.

It is a circuit diagram of the measurement unit of the voltage measuring device concerning Embodiment 1 of the present invention. It is a circuit diagram which shows a part of electric system of the hybrid vehicle carrying a voltage measuring device. It is a flowchart of voltage measurement control. It is a graph which shows the relationship between charging time and the voltage of a capacitor | condenser. It is a circuit diagram which shows a part of electric system of the hybrid vehicle carrying the voltage measuring device which concerns on Embodiment 2. FIG. 6 is a circuit diagram of a measurement unit of a voltage measurement device according to Embodiment 2. FIG. 6 is a flowchart of voltage measurement control according to the second embodiment. It is a graph which shows the relationship between the charge time which concerns on Embodiment 2, and the voltage of a capacitor | condenser.

Explanation of symbols

CL Battery cell C Capacitor 2 Battery cell unit 3 Voltage measuring device 41 First switch circuit (connection circuit)
45 Voltage measurement circuit (voltage measurement unit)
5 Control unit (control unit)
53 RAM (storage unit)
203 Voltage measuring device

Claims (12)

In a battery cell unit configured by connecting a plurality of battery cells in series, a connection step of connecting a capacitor to the battery cell in parallel via a connection circuit, a charging step of charging the capacitor with the battery cell, A measurement step of measuring the voltage of the capacitor as the voltage of the battery cell after disconnecting the battery cell and the capacitor, and a storage step of storing the voltage value measured in the measurement step, A battery cell voltage measurement method for measuring a series of voltage measurements by sequentially measuring the voltage for each battery cell with respect to the battery cell,
The connection circuit is configured to connect the positive electrode side of each battery cell to one terminal of the capacitor while connecting the negative electrode side of each battery cell to the other terminal of the capacitor;
In the connecting step, after measuring the voltage of one battery cell, when measuring the voltage of the next battery cell, the capacitor is connected to the next battery cell without discharging,
After completing a series of voltage measurements for a plurality of the battery cells, a rearrangement step of rearranging the measurement order of the plurality of battery cells in the next series of voltage measurements in order of the magnitude of the voltage value measured this time. Furthermore, the voltage measuring method of the battery cell characterized by the above-mentioned. In the voltage measurement method of the battery cell according to claim 1,
In the rearrangement step, the measurement order of the plurality of battery cells is determined for each series of voltage measurements, such that the voltage values are arranged in ascending order and the voltage values are arranged in descending order. A method for measuring voltage of a battery cell, wherein the voltage is switched alternately. In a battery cell unit configured by connecting a plurality of battery cells in series, a connection step of connecting a capacitor to the battery cell in parallel via a connection circuit, a charging step of charging the capacitor with the battery cell, A measurement step of measuring the voltage of the capacitor as the voltage of the battery cell after disconnecting the battery cell and the capacitor, and a storage step of storing the voltage value measured in the measurement step, A battery cell voltage measurement method for measuring a series of voltage measurements by sequentially measuring the voltage for each battery cell with respect to the battery cell,
The connection circuit connects a positive side of an odd-numbered battery cell in a series connection among the plurality of battery cells to one terminal of the capacitor and a negative side of the odd-numbered battery cell to the other side of the capacitor. The positive electrode side of the even-numbered battery cells in the series connection among the plurality of battery cells is connected to the other terminal of the capacitor and the negative electrode side of the even-numbered battery cell is connected to the capacitor. It is configured to be connected to one terminal,
In the connecting step, after measuring the voltage of one battery cell, when measuring the voltage of the next battery cell, the capacitor is connected to the next battery cell without discharging,
In the measurement step, the plurality of battery cells are grouped into an odd group consisting of odd-numbered battery cells in an order of arrangement in series connection and an even group consisting of even-numbered battery cells in an order of series connection. A voltage measurement method for battery cells, comprising: measuring the voltage of the battery cells included in the other group after measuring the voltage of the battery cells included in any one group. In the battery cell voltage measurement method according to claim 3,
After completing a series of voltage measurements for the plurality of battery cells, the measurement order of the plurality of battery cells in the next series of voltage measurements in each of the odd group and the even group is determined by the voltage value measured this time. The battery cell voltage measurement method further comprising an in-group rearrangement step of rearranging in order of size. In the battery cell voltage measurement method according to claim 4,
In the group rearranging step, in the group in which the voltage is measured first in the next series of voltage measurements, the measurement order of the plurality of battery cells is arranged so that the magnitude of the voltage value measured this time is in descending order. On the other hand, in the group in which voltage measurement is performed later in the next series of voltage measurements, the measurement order of the plurality of battery cells is rearranged so that the magnitudes of the voltage values measured this time are in ascending order. Battery cell voltage measurement method. In the battery cell voltage measurement method according to any one of claims 3 to 5,
In the group rearrangement step, each time a series of voltage measurements for a plurality of the battery cells is completed, the order of the group for voltage measurement first and the group for voltage measurement later is switched. Method. In a battery cell unit configured by connecting a plurality of battery cells in series, a capacitor connected in parallel to the battery cell via a connection circuit, a voltage measuring unit for measuring the voltage of the capacitor, and the capacitor After connecting the battery cell in parallel via the connection circuit and charging the capacitor with the battery cell, the parallel connection between the capacitor and the battery cell is disconnected, and the voltage of the capacitor is measured by the voltage measuring unit. A control unit for measurement and a storage unit for storing the voltage value measured by the voltage measurement unit are provided, and a series of voltage measurements are performed by sequentially measuring the voltage for each of the battery cells. A battery cell voltage measuring device comprising:
The connection circuit is configured to connect the positive electrode side of each battery cell to one terminal of the capacitor while connecting the negative electrode side of each battery cell to the other terminal of the capacitor;
The controller is configured to measure the voltage of one battery cell and then connect the capacitor to the next battery cell without discharging the capacitor when measuring the voltage of the next battery cell. In addition, after the series of voltage measurements for the plurality of battery cells is completed, the measurement order of the plurality of battery cells in the next series of voltage measurements is rearranged in the order of the voltage values measured this time. A voltage measuring device for a battery cell. The voltage measuring device for a battery cell according to claim 7,
The control unit alternates the measurement order of the plurality of battery cells for each series of voltage measurements, such that the voltage values are arranged in ascending order and the voltage values are arranged in descending order. A voltage measuring apparatus for battery cells, wherein In a battery cell unit configured by connecting a plurality of battery cells in series, a capacitor connected in parallel to the battery cell via a connection circuit, a voltage measuring unit for measuring the voltage of the capacitor, and the capacitor After connecting the battery cell in parallel via the connection circuit and charging the capacitor with the battery cell, the parallel connection between the capacitor and the battery cell is disconnected, and the voltage of the capacitor is measured by the voltage measuring unit. A control unit for measurement and a storage unit for storing the voltage value measured by the voltage measurement unit are provided, and a series of voltage measurements are performed by sequentially measuring the voltage for each of the battery cells. A battery cell voltage measuring device comprising:
The connection circuit connects a positive side of an odd-numbered battery cell in a series connection among the plurality of battery cells to one terminal of the capacitor and a negative side of the odd-numbered battery cell to the other side of the capacitor. The positive electrode side of the even-numbered battery cells in the series connection among the plurality of battery cells is connected to the other terminal of the capacitor and the negative electrode side of the even-numbered battery cell is connected to the capacitor. It is configured to be connected to one terminal,
The controller is configured to measure the voltage of one battery cell and then connect the capacitor to the next battery cell without discharging the capacitor when measuring the voltage of the next battery cell. In addition, the plurality of battery cells are grouped into an odd group consisting of odd-numbered battery cells arranged in series and an even group consisting of even-numbered battery cells arranged in series. An apparatus for measuring a voltage of a battery cell, comprising: measuring a voltage of the battery cell included in the other group after measuring the voltage of the battery cell included in any one group. The voltage measuring device for a battery cell according to claim 9,
The control unit, after finishing a series of voltage measurements for the plurality of battery cells, measures the measurement order of the plurality of battery cells in the next series of voltage measurements in each of the odd group and the even group. A voltage measuring device for battery cells, wherein the voltage values are rearranged in order of magnitude. In the voltage measuring device of the battery cell according to claim 10,
In the group that measures voltage first in the next series of voltage measurements, the control unit rearranges the measurement order of the plurality of battery cells so that the magnitude of the voltage value measured this time is in descending order, In a group in which voltage measurement is performed later in the next series of voltage measurement, the measurement order of the plurality of battery cells is rearranged so that the magnitude of the voltage value measured this time is in ascending order. Voltage measuring device. In the voltage measuring device of the battery cell according to claim 11,
The said control part switches the order of the group which measures voltage first, and the group which measures voltage later after finishing a series of voltage measurement with respect to the said several battery cell, The voltage measuring apparatus of the battery cell characterized by the above-mentioned.

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